LES Simulation of Wind-Driven Wildfire Interaction with Idealized Structures in the Wildland-Urban Interface

Simeoni

2021

Fire

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In this study, a time-dependent investigation has been conducted to numerically analyze the impact of wind-driven surface fire on an obstacle located on sloped terrain downstream of the fire source. Inclined field with different upslope terrain angles of 0, 10, 20, and 30° at various wind-velocities have been simulated by FireFoam, which is a large eddy simulation (LES) solver of the OpenFOAM platform. The numerical data have been validated using the aerodynamic measurements of a full-scale building model in the absence of fire effects. The results underlined the physical phenomena contributing to the impact of varying wind flow and terrain slope near the fire bed on a built area. The findings indicated that under a constant heat release rate and upstream wind velocity, increasing the upslope terrain angle leads to an increase in the higher temperature areas on the ground near the building. It is also found that raising the inclined terrain slope angle from 0 to 30°, results in an increase in the integrated temperature on the surface of the building. Furthermore, by raising the terrain slope from 0 to 30°, the integrated temperature on the ground for the mentioned cases increases by 16%, 10%, and 13%, respectively.

Section: Geometrical Model and Boundary Conditionsmentioning

confidence: 99%

“…Continuity, momentum, energy, species, and state equations [35] are presented in Equations ( 3)- (7):…”

Section: Numerical Modelingmentioning

confidence: 99%

Numerical Investigation of the Effect of Sloped Terrain on Wind-Driven Surface Fire and Its Impact on Idealized Structures

Edalati-nejad

Simeoni

2021

Fire

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“…The fire increases radiation in some conditions l ing embers and firebrands. One of the well-studied mechanisms by whic fire disturbances interact is that wind damage increases the amount of flam intensifying the fire-resulting in unanticipated changes in vegetatio Nonetheless, wind disturbance might buffer the impacts of fire by mech discrete fuel beds [15,21].…”

Section: Fanning Effects Of Windmentioning

confidence: 99%

“…Extensive surveys have been conducted within the field to explore the various behaviours of wildfires in both still air and windy conditions [6,7]. Several studies have been devoted to the burning behaviour of fires in windy conditions and the effects of wind on flame features [8][9][10][11], burning rate [12][13][14][15], flame height and tilt angle [6,16]. Further existing studies have been conducted on the effects of ambient wind velocity and heading on a fire [17][18][19][20].…”

Section: Introductionmentioning

confidence: 99%

Existing Improvements in Simulation of Fire–Wind Interaction and Its Effects on Structures

Shakeriaski

Nelson

et al. 2021

Fire

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This work provides a detailed overview of existing investigations into the fire–wind interaction phenomena. Specifically, it considers: the fanning effect of wind, wind direction and slope angle, and the impact of wind on fire modelling, and the relevant analysis (numerical and experimental) techniques are evaluated. Recently, the impact of fire on buildings has been widely analysed. Most studies paid attention to fire damage evaluation of structures as well as structure fire safety engineering, while the disturbance interactions that influence structures have been neglected in prior studies and must be analysed in greater detail. In this review article, evidence regarding the fire–wind interaction is discussed. The effect of a fire transitioning from a wildfire to a wildland–urban interface (WUI) is also investigated, with a focus on the impact of the resulting fire–wind phenomenon on high- and low-rise buildings.

“…Despite the fact that a large number of experiments were conducted on this topic (Table 1), few numerical studies were made. This might be because of the complicated interplays that happen in the generation and the growth of fire whirls [67,68,92,93].…”

Section: Methanementioning

confidence: 99%

Experimental and Numerical Analysis of Formation and Flame Precession of Fire Whirls: A Review

Shakeriaski

Nelson

et al. 2021

Fire

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Fire whirls are a particular case of flame behaviour characterized by a rotating column of fire driven by intense convective heating of air close to the ground. They typically result in a substantial increase in burning rate, temperature, and flame height. Fire whirls can occur in any intense flame environment, including urban areas, particularly within combustible structures, and in wildland or forest fires. Recently, investigations on the creation of fire whirls have attracted much attention. However, most analyses are focused on fire whirl structure, formation, and controlling their unique state. In effect, revisiting the available experimental techniques and numerical simulations used in analyzing fire whirls has received less attention. In this paper, experimental arrangements including empirical set ups and employed fuels are presented in detail. Subsequently, major research progress focused on experimental studies and their laboratory setup is fully discussed, followed by the available numerical simulations, including combustion and turbulence models. Applied methodologies and chosen software in the recent numerical studies are also reviewed exclusively. Finally, the latest findings are featured, and prospective pathways are advised.